M. Vanhaelen

Direct coupling of high-speed counter-current chromatography to thin-layer chromatography. Application to the separation of asiaticoside and madecassoside from Centella asiatica

Abstract The direct coupling of high-speed counter-current chromatography to thin-layer chromatography is proposed as an efficient method for the on-line monitoring of the column effluent. It requires a simple adaptation of the fittings of a Linomat C device without modification of the software. An application to the separation of asiaticoside and madecassoside from a crude extract of Centella asiatica is presented.

Volatile constituents of Trichothecium roseum

In the course of investigation of Trichothecium roseum (Fungi Imperfecti) for its attractancy against Tyrophagus putrescentiae (cheese mite), the twenty following volatile compounds produced at a very low concentration by the microfungus were identified by gc, gc/ms, gc/c.i.ms and tlc: 3-methyl-1-butanol, 3-octanone, 1-octen-3-one, 3-octanol, octa-1,5-dien-3 one, 1-octen-3-ol, 6-methyl-5-hepten-2-ol, octa-1,5-dien-3 ol, furfural, linalool, linalyl acetate, terpineol (alpha and beta) citronellyl acetate, nerol, citronellol, phenylacetaldehyde, benzyl alcohol geranyl acetate, 1-phenyl ethanol and nerolidol. Octa-1,5-dien-3-ol and octa-1,5-dien-3-one have not been previously isolated from fungi; octa-1,5-dien-3-ol is the most potent attractant amount the volatile compounds detected by gc.

Occurrence in mushrooms (Homobasidiomycetes) of cis- and trans-octa-1,5-dien-3-ol, attractants to the cheese mite Tyrophagus putrescentiae (Schrank) (Acarina, Acaridae)

Cis- and trans-octa-1,5-dien-3-ol were identified in 15 Homobasidiomycetes; these compounds exhibited a significant attraction for the cheese miteTyrophagus putrescentiae (Schrank) (Acarina, Acaridae).

High-performance liquid chromatography determination of potential content of vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol) in resins, oils, dry concentrates and multivitamin formulations

The determination of potential vitamin D concentrations in raw materials and in multivitamin formulations by high-performance liquid chromatography is reported. Simple experimental conditions allow the rapid separation of the vitamins from their respective pro- and pre-vitamins, from their irradiation side-products and from some of their overirradiation products. Vitamin extraction is performed directly from dry concentrates, tablets and capsules, without saponification; all procedures are carried out at room temperature so as to preserve the ratio of vitamin D and pre-vitamin D present in the prepatation. The relative standard deviation is less than 1.5%.

Occurrence of a cardiac heteroside in Bersama yangambiensis

Sm,-The presence of a cardiotonic bufadienolide has been demonstrated in leaves of Bersama abyssinica (Lock, 1962). This note gives evidence for the occurrence of a similar compound in the bark of another plant of the Bersama group-Bersama yangambiensis (Toussaint, 1959). Crude extracts were prepared from various parts of Bersama yangambiensis by a modification of the method of Euw & Reichstein (1950). Tested on guinea-pigs, bark extracts were found to be about three times more toxic than leaf extract. Purification was achieved by successive extraction with diethyl ether, dichlormethane and dichlormethane-ethanol (3:2; v/v) followed by separation into eight fractions on an alumina column by eluents of increasing polarity. The last fraction, which retained the sour taste of the dichlormethane extract, was eluted by 94% ethanol-water (6:4; V/V) and was further characterized. Its dry residue developed characteristic colours when treated with concentrated sulphuric acid and was demonstrated to retain the bulk of the cardiotonic activity. This chromatographically pure extract, readily soluble in ethanol, was shown to contain the steroidal skeleton of cardiotonic heterosides by well-established reactions (Lieberman, Baljet) described by Paech & Tracey (1955). The spectral analyses were sufficiently conclusive to ascribe the bufadienolide structure to the compound. The infrared spectrum in chloroformic solution shows absorption bands at 1640-I and 1605 cm- (C=C) and 1720 cm-l (C=O) characteristic of the group CH=CH-C=O of the six-membered lactone ring of bufadienolide (Jones & Herling, 1954). However, the ultraviolet spectrum gives an absorption band at 279 m p but not the bufadienolide band at 300 mp. This may be explained by the presence of a ketonic function in position 11 or 12 ofthe cyclopentanophenanthrene molecule (Hegedus, Tamm & Reichstein, 1955). The extract also possesses the pharmacological properties of cardiotonic heteroside as defined by Chen (1963). This sour-tasting compound stops the frog heart preparation of Straub in systolic contraction (Fig. 1A) and the